A labral tear occurs when the labrum detaches from the underlying bone of the pelvis. Joint fluid enters this space and prevents the torn labrum from healing.

Labrum Form and Function

The labrum is a very tough type of cartilage which forms a gasket-like seal around the hip joint. It serves to deepen the hip socket, add stability to the hip, and lubricate the hip joint. It is attached very strongly to the underlying bone. It forms roughly three quarters of a circle, and at the bottom, a strong ligament, called the transverse acetabular ligament, joins the front and back of the labrum together. In cross section it appears like the point of a triangle, with a fine outer edge and a broad base where it attaches to the bone.

In a normal hip the ball of the femur glides smoothly beneath the labrum throughout the range of movement. If there are abnormalities of the underlying bone, or extremes of motion or force, then the labrum may become damaged.

With age the labrum may become degenerate and tear, or it may calcify and become boney. Whether or not this will cause clinical problems depends upon the individual and their level of function.